Volume 8 Issue 4, April 2008

Multiparameter flow cytometry can not only assess the phenotype and magnitude of a T-cell response, but based on effector function, its quality. As discussed here, the quality of a T-cell response is crucial for defining protective cellular immunity, and has great implications for vaccine design.

Natural killer (NK) cells are known to provide a first line of defence against viruses. Here, Lewis Lanier highlights the receptors and effector mechanisms used by NK cells in the protection against viruses and discusses how, reciprocally, viruses have evolved strategies to avoid activation of these cells.

In addition to conventional interactions between receptors and ligands on opposing cells (trans interactions), some MHC-class-I-specific receptors interact with their ligands on the same cell (cis interactions). Here, the structural characteristics and functional outcome of cisinteractions are discussed.

To avoid potential damage to the host, an inflammatory response is rapidly mobilized on detection of intracellular signals that are released from dying cells. Much has been learned about these 'danger' signals, but several key issues remain unresolved, as discussed by the authors.

Maintenance of haematopoietic stem cells occurs in niches, but much discussion still surrounds the precise site and nature of these niches. Here, Mark Kiel and Sean Morrison review various niche models that are compatible with the recent published data.

The development of a diverse B-cell repertoire depends on genetic rearrangement and hypermutation at the B-cell receptor (BCR) loci. This Review describes which DNA polymerases might be involved in these DNA transactions and therefore contribute to BCR diversity.

In this Perspective article, Michael Starnbach and Nadia Roan discuss the public-health and social impact of sexually transmitted diseases, raising several questions that need to be addressed before these diseases can be conquered.